In this study, the influence of the needle profile of UREA-SCR Injector on characteristics of flow was examined. The maximum needle lift and needle velocity were varied to analyze the characteristics of mass flow rate of the Urea-SCR Injector resulted thereby. The results obtained from the examination showed the total jet amount and average flow coefficient increased in accordance with the reduced needle velocity under the condition of needle profile operation set in this study. On the contrary, the effects of varied maximum needle lift on the total jet amount and average flow coefficient appeared insignificant. Such analytic results were thus estimated that they could be applicable to the design of Urea-SCR Injector as basic data.

CFD, flow coefficient, mass flow rate, needle profile, needle velocity, urea-SCR injector.